Rotary multiple contact switch



March 5, 1957 F. KRAHULEC 2,784,266

ROTARY MULTIPLE CONTACT SWITCH Original Filed March 1, 1949 2 Shets-Sheet 1 IN VEN TOR.

March 5, 1957 F. KRAHULEC 2,784,266

ROTARY MULTIPLE CONTACT SWITCH Original Filecj March 1, 1949 2 SheetsSheet 2 INVENTOR.

E'eci life/2M1? BY United States Patent ROTARY MULTIPLE CONTACT SWITCH Fred Krahulec, Skokie, 111., assignor to A. C. Nielsen Company, Chicago, Ill., a corporation of Illinois j ZClaims. (Cl.200

The present invention relates to a rotary multiple contact switch and, more particularly, to a multiple contact switch having means for adjusting the position and surface of engagement of a contact element. This application is a division of a copending application Serial No. 78,921 filed March 1, 1949, now Patent No. 2,658,963, and assigned to the same assignee as the present application.

- Multiple contact rotary switches have many applications. Rahmel Patent No. 2,484,734 discloses an arrangement in which a multiplecontact switch is employed in connection with a device for recording the listening habits of wave signal receiver users, the switch being used to convert variable positions to a plurality of uniformly spaced indications and records thereof on a recording element or tape. By virtue of employing such a switch which in effect serves as a channelizing switch, the traces produced on such a recording element or tape may, for example, be equally spaced transversely of the tape regardless of the actual relative relationship of the different channels with respect to frequency. Where a multiple contact switch is employed in connection with recording devices of the type mentioned, it is essential that the contact positions be adjustable and also that the effective Widths of the contacts be adjustable. This is because the various channels to which a wave signal receiver is likely to be tuned are spaced in quite a haphazard manner across the frequency spectrum. Consequently, it is essential that the positions of these contacts may be adjustable so that effectively, as far as the recording element is concerned, the channels are equally spaced. It will, furthermore, be apparent to one who has had any contact with tuning a radio receiver that certain stations may be tuned in over a substantial area on the tuning dial, whereas other stations are tuned in on only a very small increment of the tuning dial. Obviously to record correctly the tuning condition of the receiver, it is essential that such variable positions of the tuning dial for the same channel will effectively control only a single contact of the rotary switch;

Such a rotary multiple contact switch must be associated with the wave signal receiver in such a manner that tuning of the receiver causes movement of the switch. It is important, therefore, that such a rotary switch have a very low torque so as not to interfere with the tuning action to any substantial extent, since the user of the receiver should generally be unaware of any different receiver operation caused by attachments to the receiver.

Accordingly, it is an object of the present invention to provide a new and improved rotary multiple contact switch.

- It is .another object of the present invention to provide a rotary multiple contact switch in which the contacts may bev selectively positioned in various ways with respect to each other and in which by limited movement 2,784,266 Patented Mar. 5, 1957 of the contacts the effective width thereof may be con trolled.

A further object of the present invention is to provide a new and improved multiple contact switch having very low torque requirements.

A still further object of the present invention is to provide a rotary multiple contact switch of sturdy, foolproof construction, in which wiping action of the switch contacts occurs to insure good electrical engagement between adjacent conducting parts.

Further objects and advantages of the present inven tion will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the present invention, reference may be had to the accompanying drawings, in which:

Fig. 1 is a perspective view of one embodiment of a multiple contact rotary switch associated with the resonant frequency varying device of a wave signal receiver;

Fig. 2 is an enlarged sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a perspective view of one of the contacts of the rotary multiple contact switch of Fig. 1;

Fig. 4 is an elevational view of a rotary multiple contact switch illustrating a modification of the present invention;

Fig. 5 is a sectional view taken on line 5-5 of. Fig. ,4;

Fig. 6 is an elevational view of a rotary multiple con-- tact switch illustrating still another embodiment of the present invention;

Fig. 7 is an elevational view of the switch of Fig. 6 viewed from the opposite side to that shown in Fig. 6;

Fig. 8 is a top view of the multiple contact switch shown in Fig. 6 of the drawings; and

Fig. 9 is a perspective view showing the multiple contact switch of Fig. 6 associated with the tuning apparatus of a wave signal receiver.

Although the rotary switch of the present invention has many different applications, it is especially adapted for use with devices and apparatus for recording the listening and/or viewing habits of wave signal receiver users where instrumented methods for obtaining this information are employed. By instrumented method is meant a method whereby information with respect to the listening habits of wave instruments or devices associated with the various wave signal receivers of a representative group of the public so as continuously to record with respect to time the tuning condition of such receivers, thereby providing the basic information from which an analysis can be made.

it will be understoodwave signal receivers economic afiluence, etc. are accounted for on a weighted basis.

In any particular locality it has been found that wave signal receivers are tuned to the various stations of a particular group of stations almost exclusively. By that is meant that in any particular area, perhaps four to eight stations are regularly listened to and although the receiver may be capable of receiving many other-stations, it is rarely tuned to signal receiver across the frequency spectrum for a presignal receiver users is obtained by such other stations for reasons. such as poor reception, duplication of program,. or' the like. Consequently, if the tuning position .of a. wave determined number of channels usually tuned in by the receiver would be used'to control a predetermined number of contacts of a multiple contact switch, it is apparent that the operation-of such'switch in response to the tuning of the receiver may be used to producea controlfunction such as.recording the. tuning condition ofjthereceiver directly on. a recording. element or performing any similar function.

Referring now to Figs. 1. to 3 of the, drawings, ,there is illustrated somewhat schematically. the. resonant frequency varyinglmeans, generally designated at 30, of a. conventional wave signal receiver. This resonant frequency varying means has been specifically illustrated as a. variable capacitor, although it might equally well comprisesome other. suitable device. Associated with the resonant frequcnoyvaryingmeans. is. a. multiplev contact. rotary switch; 31 forming one. embodimentof thepresentinven tion. As. illustrated, the rotary switch. 31 comprises an insulating support 32 which is suitably mounted adjacent thercsonant frequency varying means .30 of awave signal receiver. Mounted onthe insulating. support 32 isan adjustable element generally designated at 33, for supporting a stationary contact support 34 in theform of a portion of a torroid, preferably formed of insulating material. A complete torroid could be employed-but since with conventional wave signal receivers only about180 degrees of a tuning dial are employed, a portion of a torroid is sufficient.

Mounted at spaced points along. the torroid portion 34 are a plurality of stationary contacts 35, which contacts, although termedstationary contacts, are capable. ofhavi'ng limited relative movement. shownin Figs. 2 and 3, each comprise a triangularshaped member having substantially zero widthat one end thereof and an appreciable width at the other end thereof and.

are'adapted to be bent around the torroid portion 34 so as to form a plurality of spaced contacts, the spacing of which may be adjusted in any predetermined manner. These contacts 35 are adapted to be electrically engagedin a sequential manner by a movable switch armv 37 pivotally mountedabout the geometrical center of the torroidhavingtheportion 34. The switch arm 37 in moving through an angle of 180 degrees or thereabouts, successively engages the, contacts 35. These contacts 35 will be positioned-'in various ways.along the torroid portion.34 in dependence upon the particular channels. to which. the associated wave signal receiver is likely to be tuned, thereby providing adjustably positioned contacts.

IllfOl'dCl to provide variable contact widths, the contacts 35"'may be rotated about the cross sectionof the torroid.

switch arm 37 is directly moved with rotation ofthe tun.--

ing-shaft; When the'tuning shaft'is in a predetermined'po:

sition': denoting a particular channel to whichthe receiver, is:tuned,,a particular one of thecontacts 35is engagedby the switch arm 37 and a suitable control circuit may be rendered effective to perform any'desired' control function-for recording the tuning condition of the receiver.' The a-detailszof 'one such control arrangement; are, fully" disclosed in. the Rahinel patentreferred to above.

. In .viewof the-detailed description included above, particularlyrwith.referenceto Figs. 1 to 3 of;' the drawings,

thezopera-tionw of i the rotary'switch" described above will berapparent to those skilled in the=art and'no further di'se cussionrhereof is included hereinz It will be ob'vious. that These contacts 35, best there has been provided a variable position, variable width contact, multiple contact switch.

Referring to Figs. 4 and 5 of the drawings, there is disclosed another embodiment of the present invention in the form of a rotary switch generally designated at 45. This rotary switch also comprises an insulating support designated as. 4.6, which has anarcuate. groove 47 defined therein. A rotatable switch arm 48 is mounted for rotation upon a shaft 49 journaled in suitable supports, such as 50; and 51', which may form an integral assembly with the insulating support 46. As illustrated, the movable switch arm 48 isbiased by means of. a tension; spring 52 against a stop53, thereby insuring return ofvsaid arm 48 to its initial position shown in Fig. 4 when any'forcetending to rotate the shaft 49 against the bias of the spring 52 is removed. Such an arrangement lends itself very well for use with a force transmitting device capable of transmitting a force in only one direction, a well known example'of which is the Bowden Wire.

In accordance withthe present invention, there are-supported within the arcuate groove 47 a plurality of contacts'55. having an elongated contact surfaceadapted to be. engagedby the movable switch arm 48. If the elon gated contact surface ispositioned substantially tangen tially 'to the groove47, it is apparent that the switch arm- 48 contacts the maximum effective area thereof or, in. otherwords, a maximum efiective contact Width is provided; On. the other hand, if the elongatedcontact portion'. is substantially perpendicular to a tangent to' the groove 47, a very narrow-effective contactisprovidedi This will. be obvious'fromcanexamination of Figs; 4and 5 of the; drawings. Preferably, as is best shown in Fig. 5, each-contact is in effect the head of a screw 57 which is clampedby, means of'a' nut 58 into' a predetermined position along the groove 47 and: also with a predetermined orientation to providethe desired effective contact width. A. 'suitableelectrical terminal 59 towhich electrical con ncctions. can readily be made, is also clamped into'position by. the screw 57 and. the nut 58.

It. will be understood that theshaft. 49. may becon nected in a suitable manner, such' as by a Bowden wire, with thetuning shaft of a wave signal receiver, with'the' result that the various channelsto which the wavesignal receiver is tuned will selectivelycausepredetermined cor responding contacts to be engaged by the movable. switch arm.48..

Referringnow-toFigs. 6; to 9, inclusive, of. the drawings, there. is illustrated stillanother-modification ofthe pres ent. invention in the form of a multiple contact. rotary switch generally designated by-the reference numeral 65.

This. switch, likev the preceding embodiments, also: com

prises a stationary insnlatingsupport 66,,whichmay'be; mountedin. any suitable manner adjacent awaveasignal;

receiverbymeans of a suitable angle plate67 fastenedby'" fastening means 68 to a support generally designated at 69'. The. insulating support .66 and the angle member 67. sup-- port for relativerotation with respect thereto a. suitable rotatable shaft 70 to which is-fixed a rotatable: disc 71 having mounted thereon a suitable movable switchtarmn trasted with the relatively stationary contacts. in. the: switches 31 and 45, which are. providedwith. variable:

widths;

In. accordance with the present invention,- a': plurality of relatively. stationary contactsdesignated as 73a, 73b,.

73c, 73d, and'73'e are provided, which are preferablyiim the form of, resilient. wire-like: contacts: adjustably; supported" from, suitable supporting. means 74* mounted; on: the stationary insulating, support. 66. The-supporting means. 74, arerotationally adjustable sov thatthe angular:

position of the particular contact arm 73 may be adjusted in any desired manner. Moreover, the contact arms 73 extend through suitable openings in the members 74 and are clamped thereto by suitable clamping means such, for example, as the screws 75. By changing the length of the contact portion 73 extending out of the support 74, the efiective position of the contacts may be controlled in any desired manner and by changing the angular relationship of the wire-like contacts 73 any desirable width of the rotatable switch arm 72 may be rendered etfective to produce the desired effective variable width contact.

For the purpose of causing rotation of the disc 71 and consquently the movable contact arm 72 in response to a force applied thereto in only one direction, there is provided a torsion spring 77 which tends to bias the rotatable disc 71 to the position shown in Fig. 8 of the drawings. The rotatable shaft 70 is provided with a pulley-like member 79 about which the movable portion of one end of a Bowden wire 80 may be wrapped, as indicated at 80a, the Bowden wire being suitably supported from the stationary insulating support 76 by means of the member 81.

In Fig. 9 of the drawings there is illustrated the interconnection between the switch 65 and the wave signal receiver, only the resonant frequency varying means 82 of which is shown. The end 80b of the movable portion of the Bowden wire 80 remote from the switch 65 is illustrated as being wrapped around a suitable drum 83 which is rotatable with the tuning shaft of the associated wave signal receiver. Rotation of the tuning shaft will apply a tensile force to the movable portion of the Bowden wire 80 with the result that the disc 71 is rotated against the torsional force of the spring 77, and the stationary contacts 73 are selectively rendered efiective as they are engaged by the movable switch arm 72 Although only five stationary contacts 73 are illustrated, it will be apparent that a great many more might be included if additional contacts are necessary or desirable. The members 74 are connected to suitable connectors 84 to which electrical connections can readily be made.

From the above description it will be apparent that there have been provided various embodiments of a position switch wherein a multiple contact rotary switch giving effective angular contact position and variable width contacts is provided. While there have been disclosed and described various embodiments of the present invention it will be obvious to those skilled in the art that numerous changes and modifications may be made without departing from the spirit and scope of the present invention in its broader aspects and it is aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope or" the present invention.

What is claimed as new and desired to Letters Patent of the United States is:

1. In a rotary multiple contact switch, an insulating support in the form of an arcuate rod, a plurality of ring-shaped contacts each of triangular shape when in developed form, encircling said rod at spaced points therealong, movable means for selectively engaging different ones of said contacts, and means responsive to the relative position of said ring-shaped contacts on said support for selectively and individually adjusting the eflective width of each of said contacts with respect to contacting engagement with said movable means.

2. In a rotary multiple contact switch, an insulating support in the form of an arcuate rod, a plurality of ring-shaped contacts each of triangular configuration when in developed form, encircling said rod at spaced points therealong, movable means for selectively engaging different ones of said contacts, and means responsive to rotation of one of said ring-shaped contacts around the center of the cross section of said arcuate rod for selectively adjusting the etfective width of said one con tact with respect to contacting engagement with said movable means.

be secured by References Cited in the file of this patent UNITED STATES PATENTS 505,687 Watts Sept. 26, l893 879,300 Newman Feb. 18, 1908 900,529 Hansen Oct. 6, l908 1,528,654 Cancienne Mar. 3, 1925 1,751,920 Holbrook et a1 Mar. 25, 1930 1,982,982 Crozier Dec. 4, l934 2,068,227 Cutler et al. Jan. 19, 1937 

